Oh dear. I'm going to have to 'fess up and say that I've got one on my road bike. In my defence it is custom steel, and the man who built it seemed to take it as a given that my name would be on it, so I was too polite to say otherwise. I've always had a few misgivings about it being there, but on the other hand, the bike is not set up as a racing bike, so there is no danger that I look like I'm trying to be a pro.
EDIT & judging by the post above it does seem that this does appear to be the norm in certain traditional frame building circles.